Rainbow Fun Facts

Aug 24, 2018

#FunFactFriday!

Here are some things you may not have known about rainbows.

No two people see the same rainbow, in fact even our individual eyes see slightly different rainbows. If someone appears to be standing under a rainbow you can see, they will see a different rainbow at the same angle but further away.

The sky within a primary rainbow is brighter than the sky outside of the arc. This is due to the fact that the millions of droplets needed to make a rainbow are spherical and overlap to create white light. At the edge however, these colored discs don’t overlap so display their individual colors producing the rainbow arc.

A “double rainbow” is where a second, much fainter arc can be seen outside of the primary arc. This is caused by the light reflecting twice inside the water droplets. As a result of this double reflection the colors of the second arc are inverted with violet on the outer edge and red on the inner edge.

The dark, unlit sky between the primary arc and secondary arc is called Alexander’s band, after Alexander of Aphrodisias who first described it in 200 AD.

In 1666, Isaac Newton added indigo and orange to give us the seven-colored Roy G. Biv that we all know and love today. However, in China rainbows are considerer to contain just five colors.

A “moonbow” is a rare lunar rainbow or night time rainbow produced by light from the moon. Our eyes see it as white even though all colors are faintly present.